VS Code Codex chat should support drag-and-drop file references from Explorer

What version of the IDE extension are you using?

openai.chatgpt 26.727.40816-darwin-arm64

What subscription do you have?

ChatGPT Plus

Which IDE are you using?

VS Code 1.131.0

What platform is your computer?

Darwin 25.5.0 arm64 arm

What issue are you seeing?

In the Codex VS Code extension, dragging a file from the VS Code Explorer into the Codex chat input does not create a usable file reference.

This makes file selection less user-friendly because the current workaround is to right-click a file, choose Copy Relative Path or Copy Path, and manually paste it into the chat.

Actual behavior:
The file is not inserted as a usable Codex file reference.

What steps can reproduce the bug?

1. Open VS Code with a workspace folder.
2. Open the Codex chat panel.
3. In the VS Code Explorer, drag a file from the workspace into the Codex chat input.
4. Drop the file into the chat input.

What is the expected behavior?

Dropping a file from the VS Code Explorer into Codex chat should insert a workspace-relative file reference, or otherwise attach/reference the file in a way Codex can understand.

Suggested behavior:

• If the file is inside the current workspace, insert its relative path.
• If multiple files are dropped, insert multiple file references.
• If a file is outside the workspace, either insert the absolute path or show a permission/confirmation prompt.

Additional information

Why this matters:
Codex already supports working with files when paths are typed manually. Drag-and-drop would make the same workflow much more discoverable and user-friendly, especially for users who navigate project files visually in the Explorer.

This is a UX improvement request for the VS Code extension chat input. It is not asking for arbitrary file upload behavior; inserting the same file path/reference that users can already paste manually would be enough.

Start at the VS Code extension's Codex chat input and reproduce the Explorer drag-and-drop flow with workspace and multiple-file cases. Done means dropping a workspace file inserts a usable relative reference, while outside-workspace behavior is defined and verified. No source file or test is named in the issue, so the relevant input handling and test location must first be located.